Question: $\left(-9x - 9\right)^2 = \ ?$
Explanation: $= \left(-9x - 9\right)\left(-9x - 9\right)$ $= -9x \cdot \left(-9x - 9\right) - 9 \cdot \left(-9x - 9\right)$ $= \left( -9x \cdot -9x \right) + \left( -9x \cdot -9 \right) + \left( -9 \cdot -9x \right) + \left( -9 \cdot -9 \right)$ $= 81x^2 + \left( -9x \cdot -9 \right) + \left( -9 \cdot -9x \right) + \left( -9 \cdot -9 \right)$ $= 81x^2 + \left( 81x + 81x \right) + \left( -9 \cdot -9 \right)$ $= 81x^2 + 162x + \left( -9 \cdot -9 \right)$ $= 81x^2 + 162x + 81$